The term micro electromechanical system (MEMS) or micro mechanical system/structure is often used to refer to small integrated devices or systems that combine electrical and mechanical components. When focusing on the micro mechanical parts, the term “micro mechanical system” may be used to describe small integrated devices or systems which comprises one or more micro mechanical elements and possibly, but not necessarily, electrical components and/or electronic components.
Micro mechanical systems may be used as, for example, actuators, transducers or sensors, e.g. pressure sensors. Pressure sensors are nowadays mass products in automobile electronics and consumer goods electronics. For many of these applications, systems are used in which the sensor is integrated in an application-specific integrated circuit (ASIC). For example, Infineon Technologies AG offers such a system as a side-airbag sensor.
In particular, the mechanically active elements of a micro mechanical system may typically require relatively complex structures, such as recesses, beams, cantilevers, undercuts, cavities etc. Possibly, a relatively high number of manufacturing steps are required. Furthermore, the process used for performing the micro mechanical system may need to be compatible with possible subsequent manufacturing steps that are used for creating electrical and/or electronic components, for example.
Micro mechanical systems or structures (MMS) may comprise deflectable structures such as membranes. A Micro electromechanical structure (MEMS) may comprise one or more micro mechanical structures whose deflectable structure may be deflected electrically (actuator). Alternatively or in addition the MEMS may provide an electrical signal responsive to a deflection of the deflectable structure of the MMS (sensor). Movement of the deflected structure may lead to mechanical stress. Thus, there is a need to provide micro mechanical structures with improved durability and/or deflection performance.